/*
 * Alloy Analyzer
 * Copyright (c) 2002 Massachusetts Institute of Technology
 *
 * The Alloy Analyzer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The Alloy Analyzer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the Alloy Analyzer; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package alloy.ast;


/**
 * A class subclassed by any AST node representing a
 * constant expression (none, univ, and iden for now).
 */

public abstract class GenericConstExpr extends LeafExpr {

    /**
     * index of type expr in child list
     */
    private static final int TYPEEXPR_INDEX = 0;
    
    public GenericConstExpr(Location location_, Expr typeExpr_) {
        super(location_, typeExpr_);
    }


    public GenericConstExpr(Expr typeExpr_) {
        super(Location.UNKNOWN, typeExpr_);
    }



    //GET AND SET METHODS

    /**
     * gets the type expr of this
     * DEPRACATED: should be removed when dependent code is fixed
     */
    public Expr getTypeExpr() {
    	//Dbg.chk(false, "tried to get expression of a constant");
        return (Expr)childAt(TYPEEXPR_INDEX);
    }

    /** set the TypeExpr of this */
    public void setTypeExpr(Expr newChild_) {
        setChild(TYPEEXPR_INDEX, newChild_);
    }

    /**
     * accept an AST visitor
     * @param visitor_ the visitor
     */
    protected void acceptVisitor(ASTVisitor visitor_) {
        visitor_.visit(this);
    }

    /**
     * accept a returning AST visitor
     * @param visitor_ the visitor
     * @return the Object returned by the visitor
     */
    protected Object acceptReturnVisitor(ASTReturnVisitor visitor_) {
        return visitor_.visit(this);
    }
    
    public String toString()
    {
        return nodeString();
    }

}






